Three series-connected capacitors, C1, C2 and C3, with capacitances 10uF, 15uF and 27uF respectively, are connected in parallel with a 15uF capacitor and a 150V DC source. Calculate:
a) Equivalent capacitance of the circuit
b) The total charge QT stored by the parallel connected capacitors,
c) Charges Q1-Q3 on C1-C3 respectively.